I'd never really given much thought to wearing primer until I went makeup shopping for my wedding day. Like most brides, I wanted to make sure I looked pretty in all photos taken on the day, so I decided to buy a primer to make my makeup last longer. And that's exactly what it did.

Ever since, I've come to think of primer as an essential beauty product, and there are few days when I don't apply it after my moisturizer and under my makeup.

Primer acts as a smoothing base for whatever products you apply, and makes makeup like foundation and concealer last a lot longer than they would without it.

To prove just how well it works, I put my Smashbox primer to the test. Over the course of two separate days, I took photos to monitor how my makeup held up with — and without — primer underneath. I wore the exact same makeup products each day to see the difference the lack of primer would make.

Day 1: No primer

It looks like my makeup has completely gone.
Chloe Pantazi/INSIDER
As you can see, I don't even look like I'm wearing makeup by the end of the day. My foundation hasn't lasted the length of my workday, there's no sign of my blush, and my lipstick has vanished.

Day 2: Primer

Wearing primer made a noticeable difference.
Chloe Pantazi/INSIDER

While my makeup doesn't look exactly
like it did in the morning, wearing primer made a significant difference. My foundation stayed on evenly (though the lighting in the INSIDER office doesn't help show that), and you can still tell I'm wearing makeup.

The biggest difference I noticed was that the color corrector and concealer I wore under my eyes were still holding strong when I had primer underneath
. The bags under my eyes are far more visible by the end of the day without primer.

Without primer, I might be tempted to refresh my makeup throughout the day, using up more of my products in the process.

So, while it might seem like a non-essential beauty product, it can actually save both time and money — especially if, like me, you're lazy but want your makeup to look on-point.